1. Field of the Invention
The present invention relates to a vehicle designed to be towed underwater by a mobile support ship that provides propulsion for the towed vehicle.
2. Description of the Prior Art
Presently known are underwater towed vehicles that rely solely upon a mobile surface support ship for propulsion and maneuverability. Generally, such underwater vehicles depend upon a surface-connected umbilical cable for power and data telemetry.
Such vessels have been used for hydrography, underwater exploitation and explotation, harbor mapping and surveying, mine hunting and classification, defense and military missions, and pipe and trench monitoring. Such vessels have been equipped for underwater television monitoring, underwater photography, side scan sonar mapping, and photographic and acoustic sea floor surveys. The vessels have been used to search, identify, and locate underwater objects.
Previously known towed vehicles are described in an August, 1979, publication entitled "Remotely Operated Vehicles" published by the Office of Ocean Engineering, National Oceanic and Atmospheric Administration, U.S. Department of Commerce. Such vehicles are also described in French Pat. No. 1,499,177 and U.S. Pat. Nos. 2,359,366; 2,568,549; 2,948,251; 3,474,750; 3,613,628; 3,698,339; 3,807,342; 3,824,945; and 4,108,101.
Normally, the vertical position of previously known towed vehicles is determined by the length of the towing cable, the speed of towing and the weight of cable and vehicle. No provision, other than movement of the towing vessel, is provided for adjusting the lateral position of the towed vehicle. The vehicle either follows the towing vessel dead astern or has uncontrolled lateral movement. Changes in cable tension and angle resulting from a turn result in the towed vessel "kiting" (rising in an uncontrolled manner to the surface) or sinking.